Thanks for responding.
The problem with the word “nothing” is that, colloquially at least, the word is meant to convey a vast and sheer emptiness. A room is empty of furniture: nothing is in the room. This is true, that is, in terms of the colloquial use of the word “nothing.” But in the sense that Krauss and his fellow physicists use, the room is not empty. More to the cosmological point, in terms of the “empty” space between planets and stars et al, something is there, but we don’t know what “it” is (for now it is referred to as “dark matter”).
As for the the “uncaused cause” argument, it doesn’t work for me because of the intrinsic illogic behind it. The syllogism goes like this (and this is rooted in William Paley’s famous “watchmaker analogy”): Everything has a creator, God is that creator — but God has no creator because… well, just because: God is the First Cause, the Unmoved Mover, the Prime Mover, or however you care to frame it. So: because God is believed (key word) to be an uncaused cause, God, therefore, does not have a creator. To put this another way, believers will say the universe is far too complex to have spontaneously generated, and so the only explanation is that something more complex (God) has to account for it.
This view makes no sense because of its glaring flaw: it violates its own premise. If everything has a cause, why is God excused from this logic? If a complex “thing” (all of existence) requires something more complex to account for it, how can this Ultimate Something (God) be causeless? In other words, why does this “complexity-begets-something-more-complex” argument stop with God? On what argumentative ground can this view be supported? There is no such ground. It makes no sense to set up a premise (everything has a cause) and then conveniently exempt God from that premise simply because of a fanciful belief that God is to be defined as some Cosmic End Point, or as Tillich put it, the Ground of Being (Tillich is hardly the only person to offer this view, but I mention him because he’s the most well-known exponent of this idea). The Prime Mover argument is nothing more than a groundless belief and sheer whimsy — and whimsy doesn’t get us anywhere when it comes to understanding the nature of the world and the universe.